1、简练、开放、兼容和可扩展等原则。充分注意到因特网开放而复杂的网络环境下的安全问题。充分考虑了对传统公共电话网的各种业务，包括IN业务和ISDN业务的支持。,Page,协议栈,Page,SoftX3000,SoftPhone,IP Core,SoftX3000,SoftPhone,SIP/SIP-T,SIP,SIP,IP,IP,IP,IP,SIP协议在SoftX3000中的实现,Page,内容介绍,第一节 概述第二节 协议消息第三节 呼叫流程,Page,SIP协议消息的分类,SIP消息采用文本方式编码，分为两类：请求消息和响应消息。请求消息：客户端为了激活按特定操作而发给服务器的SIP消息。响应
2、消息：用于对请求消息进行响应，指示呼叫的成功或失败状态。请求消息和响应消息都包括SIP头字段和SIP消息字段。,Page,请求消息,Page,响应消息,Page,SIP消息命令格式,Page,响应格式,Page,内容介绍,第一节 概述第二节 协议消息第三节 呼叫流程,Page,用户注册流程,SoftX3000,SIP Phone,Page,用户注册流程,REGISTER sip:191.169.150.30 SIP/2.0From:sip:6540012191.169.150.30;tag=16838c16838To:tag=946e6f96Call-Id:1-reg191.169.150.2
3、51Cseq:2762 REGISTERContact:6540012191.169.150.251Expires:100Content-Length:0Accept-Language:enSupported:sip-cc,sip-cc-01,timerUser-Agent:Pingtel/1.2.7（VxWorks）Via:SIP/2.0/UDP 191.169.150.251,SIP/2.0 401 UnauthorizedFrom:;tag=946e6f96CSeq:2762 REGISTERCall-ID:1-reg191.169.150.251Via:SIP/2.0/UDP 191.
4、169.150.251WWW-Authenticate:Digest realm=,nonce=200361722310491179922Content-Length:0,Page,用户注册流程,REGISTER sip:2763 REGISTERContact:Pingtel/1.2.7（VxWorks）Authorization:DIGEST USERNAME=6540012,REALM=,NONCE=200361722310491179922,RESPONSE=b7c848831dc489f8dc663112b21ad3b6,URI=sip:191.169.150.30Via:SIP/2
5、.0/UDP 191.169.150.251,SIP/2.0 200 OKFrom:2763 REGISTER Call-ID:1-reg191.169.150.251,Page,SIP实体之间的SIP呼叫流程,Page,SIP实体之间的SIP呼叫流程（续）,Page,用户呼叫流程实例,在下面的报文实例中，我们基于以下约定：SoftX3000的IP地址为191.169.200.61；SIP PhoneA的IP地址为191.169.150.101；SIP PhoneB的IP地址为191.169.150.100；SIP PhoneA为主叫，SIP PhoneB为被叫，主叫先挂机；SIP Phone
6、A的电话号码为1000，SIP PhoneB的电话号码为1001。,Page,用户呼叫流程实例（SIP主叫softx3000）,INVITE sip:1001191.169.200.61 SIP/2.0From:1000191.169.200.61;tag=1c12674To:1001191.169.200.61Call-Id:call-973598097-16191.169.150.101Cseq:1 INVITEContact:1000191.169.150.101Content-Type:application/sdpContent-Length:203Accept-Language:e
7、nAllow:INVITE,ACK,CANCEL,BYE,REFER,OPTIONS,NOTIFY,REGISTER,SUBSCRIBESupported:SIP/2.0/UDP 191.169.150.101v=0o=Pingtel 5 5 IN IP4 191.169.150.101s=phone-callc=IN IP4 191.169.150.101t=0 0m=audio 8766 RTP/AVP 0 96 8a=rtpmap:0 pcmu/8000/1a=rtpmap:96 telephone-event/8000/1a=rtpmap:8 pcma/8000/1,Page,用户呼叫
8、流程实例（SIP主叫softx3000）,SIP/2.0 100 TryingFrom:CSeq:1 INVITECall-ID:call-973598097-16191.169.150.101Via:SIP/2.0/UDP 191.169.150.101Content-Length:0,Page,用户呼叫流程实例（SIP主叫softx3000）,SIP/2.0 407 Proxy Authentication RequiredFrom:tag=de40692fCSeq:SIP/2.0/UDP 191.169.150.101Proxy-Authenticate:Digest realm=,no
9、nce=1056131458Content-Length:0,Page,用户呼叫流程实例（SIP主叫softx3000）,ACK sip:1001191.169.200.61 SIP/2.0Contact:1000191.169.150.101From:tag=de40692fCall-Id:1 ACKAccept-Language:enUser-Agent:0,Page,用户呼叫流程实例（SIP主叫softx3000）,INVITE sip:2 INVITEContact:Pingtel/1.2.7（VxWorks）Proxy-Authorization:DIGEST USERNAME=10
10、00,REALM=,NONCE=1056131458,RESPONSE=1b5d3b2a5441cd13c1f2e4d6a7d5074d,URI=sip:1001191.169.200.61Via:8 pcma/8000/1,Page,用户呼叫流程实例（SIP主叫softx3000）,SIP/2.0 180 RingingFrom:tag=e110e016CSeq:2 INVITECall-ID:SIP/2.0/UDP 191.169.150.101Contact:Content-Length:0,Page,用户呼叫流程实例（SIP主叫softx3000）,SIP/2.0 200 OKFrom:183Content-Type:application/sdpv=0o=HuaweiSoftX3000 1073741834 1073741834 IN IP4 191.169.200.61s=Sip Callc=IN IP4 191.169.150.100t=0 0m=audio 8766 RTP/AVP 0 8a=rt
